images without exif data
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wirz
Oct 12, 2025, 5:45:36 PM (4 days ago) Oct 12
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Hi,
I have a project where, apart from several normal photos (as jpg), there
is one jpg that has been generated with another program. It is not a
photo and does not contain an embedded thumbnail or any other exif data.
In hugin I specify the fov and projection of the artificial image -- no
problems there. In the control points tab the image is displayed
correctly and I can manually set control points. In the openGL pano
preview the artificial image is displayed as entirely black, but in the
correct size etc (and all the other images are displayed correctly). In
the final result image (hugin_executor --stitching ...) it is also
treated as entirely black.
Do we have any explicit requirements for what data a jpg must contain to
be treated correctly? I assume the issue has something to do with the
missing exif data, but I don't know which part is required. Depending
on what data hugin seems to be missing, it might be possible to treat
the image correctly with the existing data (given that it is displayed
correctly in the control points tab).
But apart from this minor issue, I found that for mountain panos where
no horizon is visible and where it is normally hard to keep the image
straight, it is a very good method to add an image with artificially
generated mountain outlines, align all photos relative to that, and
don't include the artificial image in the final pano. That way one gets
a result that is perfectly aligned with the invisible horizon.
cheers, lukas wirz
I have a project where, apart from several normal photos (as jpg), there
is one jpg that has been generated with another program. It is not a
photo and does not contain an embedded thumbnail or any other exif data.
In hugin I specify the fov and projection of the artificial image -- no
problems there. In the control points tab the image is displayed
correctly and I can manually set control points. In the openGL pano
preview the artificial image is displayed as entirely black, but in the
correct size etc (and all the other images are displayed correctly). In
the final result image (hugin_executor --stitching ...) it is also
treated as entirely black.
Do we have any explicit requirements for what data a jpg must contain to
be treated correctly? I assume the issue has something to do with the
missing exif data, but I don't know which part is required. Depending
on what data hugin seems to be missing, it might be possible to treat
the image correctly with the existing data (given that it is displayed
correctly in the control points tab).
But apart from this minor issue, I found that for mountain panos where
no horizon is visible and where it is normally hard to keep the image
straight, it is a very good method to add an image with artificially
generated mountain outlines, align all photos relative to that, and
don't include the artificial image in the final pano. That way one gets
a result that is perfectly aligned with the invisible horizon.
cheers, lukas wirz
Bruno Postle
Oct 12, 2025, 6:12:48 PM (4 days ago) Oct 12
to hugin and other free panoramic software
Hi Lukas, the problem you are having is that images without metadata are loaded with Eev (Exposure) set to 0.0 - which is ok since the Eev of the panorama output defaults to 0.0 as well.
But when you use photos, these have Eev of 10.0 or similar and Hugin sets the output panorama Eev to the average of the input photos. This is ok until you add an artificial image without metadata - its Eev still gets set to 0.0, and it appears very dark.
The solution is to manually set the Eev of artificial image to whatever value the Eev of the panorama is.
--
Bruno
Bruno
wirz
Oct 13, 2025, 11:23:03 AM (4 days ago) Oct 13
to hugi...@googlegroups.com
Hi Bruno,
Indeed, that works. Thank you!
cheers, lukas wirz
Indeed, that works. Thank you!
cheers, lukas wirz
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